IIT JEE , AIEEE Forum - Physics , Optics

mohnish_khiani

A ray of light travels from liquid of refractive index '

' to air.If the incident beam is rotating at a rate '

',what is the angular speed of the refracted beam at the instant the angle of incidence is 30.Given

=

2 and

=1/

6.

asagwal

1/(sqrt.2)
u called it good, did u know the solution?
do u want it?

mohnish_khiani

yaa plz tell me the solution.....

siddharthsaxena

see, by snell's law r=45 degrees

no we knoW that

sin

=cnstt

so

sin(i)=[

of air] sinr

diff with respect to time

cos(i)*di/dt=[

of air]cos(r)*dr/dt

now, di/dt is

. and dr/dt we have to find.

so putting in the values

WE will get dr/dt (ans) as 1/sqrt2.

RATE ME IF IT HELPS

asagwal

sin x = sin y (let y be angle in air, x in medium)
y=45

now diif the equation to get

cosx = cos y dy/dx
now dy/dt = dy/dx *

since

= dx/dt
solve for dy/dt to get 1/^{[ ]}

2 as the answer
rate me if u like it

mohnish_khiani

thanks very much.....siddharth and asagwal